Astron. Astrophys. 326, 1252-1258
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Triggering of magnetic reconnection in the current
by shock waves
D. Odstril and M. Karlický
Astronomical Institute, 251 65 Ondrejov, Czech
Received 14 March 1997 / Accepted 27 May 1997
Interaction of a shock wave with a current sheet is investigated
by the two-dimensional numerical magnetohydrodynamic model.
In accordance with the solar coronal conditions,
the ratio of the thermal to magnetic pressures of 0.1
and the shock Alfven Mach number of about 1.25 are used.
It is found that the shock wave initiates magnetic reconnection
process in the current sheet.
Further, it is found that the post-shock situation rather than
the shock compression is a cause of the magnetic reconnection.
Interaction of the shock with the current sheet results
in formation of two shocks that propagate away from the current sheet
on opposite sides followed by a rarefaction waves region.
This dynamic situation causes the current sheet to become
gradually thinner and the magnetic reconnection process is initiated
probably due to the tearing-mode instability.
Presented results support the idea that the solar flare
can be triggered by the shock wave from a distant flare.
Key words: Magnetohydrodynamics (MHD) -
shock waves -
methods: numerical -
Sun: flares -
Sun: magnetic fields
Send offprint requests to: D. Odstril
© European Southern Observatory (ESO) 1997
Online publication: October 1, 1997
Last change: April 8, 1998